Difficulty Feeding and Jaundice in a Two-Week Old Baby

In Episode 63 of Med School Question of the Week for USMLE, Faustine Ramirez, MedSchoolCoach expert tutor, answers this medical school question: A 2-week-old infant is brought to the pediatrician’s office for an initial examination. She was born at home at 38 weeks’ gestation to a 26-year-old primigravid woman. The parents have no medical problems, and the pregnancy was uncomplicated. They are concerned that she has difficulty latching when she breastfeeds and takes a long time to feed. She does not wake up regularly for feeds every 2-3 hours. Vital signs are within normal limits. Weight is in the 74th percentile, length is in the 48th percentile, and head circumference is in the 92nd percentile. On examination, the infant has large, soft fontanels, a large protruding tongue and her face appears puffy. She has a hoarse cry when she is unswaddled. Her skin is jaundiced and slightly dry. Cardiac examination is unremarkable. The abdomen is soft, non distended, without hepatosplenomegaly. She has a small reducible umbilical hernia. Her suck is slightly uncoordinated and she has mild hypotonia. Which of the following is most likely to have predicted these findings?

• Prenatal ultrasound
• Maternal glucose tolerance testing
• Paternal karyotype analysis
• Routine newborn screening
• Amniocentesis
• Prenatal inhibin levels
• Prenatal alpha-fetoprotein levels
• Maternal RPR testing